The present invention relates to a tape or band for wrapping around packages wherein the tape is made of a thermoplastic resin, and is usually operated upon for packaging by a packaging machine, which will be described later.
Conventionally, packaging tapes made of thermoplastic resin materials such as polyethylene, polystyrene, etc. have been widely used, which generally has a thickness of 1.0 mm and width of 15 mm. However, it has been found that the conventional packaging tape often produced objectionable cracks or splits in the longitudinal direction of the tape.
In order to overcome such objections, numerous attempts have been made. Some are improvements in a tape and others in a packaging machine.
With respect to the improvements in the tape, an improved tape has been suggested which is embossed entirely on either or both surfaces of the tape to prevent the resin tape from cracking or splitting in the lengthwise direction thereof. One technical doctrine of embossing the tape is based upon the fact that the embossment effectively disorders the arrangement of micelle particles within the thermoplastic resin materials, which has succeeded in preventing the disadvantages of cracking or splitting in the lengthwise direction of the tape.
While the objectionable splitting has been overcome, however, another shortcoming has appeared in that the rigidity of the tape is unsatisfactorily low, resulting in that the tape cannot be delivered to or fed through the packaging machine in a packaging operation. Further, I have found another shortcoming in that a strain or flection is produced on both sides of the tape, and therefore the tape does not lie straight, but is abnormally bent and/or waved. This is, I believe, due to the fact that when embossments are formed on the tape, pressure applied on the tape for forming the embossments is not uniform on every part of the tape. Therefore, an excessive pressure on one side or a part of the tape causes the strain to be produced in the tape. When such a strain or flection is produced on the tape, the tape cannot be delivered in a smooth manner through the packaging machine, and the tape does not closely contact or adhere to an article, such as corrugated cardboard boxes to be packed.
Accordingly, an object of the present invention is to provide a novel thermoplastic resin packaging tape which meets with the various requirements for a smooth packaging operation.
Another object of the present invention is to provide a thermoplastic resin packaging tape which can closely contact and adhere to an article to be packed, without producing waves on the sides of the tape.
Other objects and features of the present invention will become apparent from the detailed description of the preferred embodiment thereof, which will be read with reference to the accompanying drawings.